1. T. Vicsek, Fractal Growth Phenomena, ( World Scientific, Singapore, 1989 )
2. J. Feder, Fractals, ( Plenum, New York, 1988 )
3. D.A. Kessler, J. Koplik and H. Levine, Adv. Phys. 37, 255, (1988)
4. P. Meakin, in Phase Transitions and Critical Phenomena, ed. by C. Domb and J.L. Lebowitz (Academic, New York, 1988) Vol. 12, p. 335
5. D. Bensimon, L.P. Kadanoff, S. Liang, B. Shraiman and L. Tang, Rev. Mod. Phys. 58, 977, (1986)